Food storage containers are generally made of a plastic material such as polypropylene or polyethylene polymers or copolymers. Such containers are normally fairly rigid, but may be subject to some amount of flexure especially where the lid or cover is arranged to be peeled off of the container mouth. Most such container/lid configurations provide a sealing bead or rim along the upper wall of the container with a mating channel on the lid which engages the bead as well as the adjacent inner and outer surfaces of the container wall. Such sealing arrangements generally require considerable effort to force the lid onto the sealing bead during the closing procedure and perhaps greater effort to peal the lid away from the container during the opening process. While some lids are provided with one or more outwardly extending tabs to accommodate a user's fingers, the opening procedure may be quite difficult for a person suffering from arthritis or tendinitis. In addition, the lids of such sealable containers often become distorted through heating, dishwashing or refrigeration procedures making lid replacement difficult or impossible. In addition containers designed for microwave use are generally provided with a separate vent located in the lid for preventing pressure build up.
In some designs a separate sealing member such as an O-ring or annular gasket is disposed between the container rim and the lid channel to provide a more secure seal. Such designs may rely on frictional forces to maintain the lid in place on the container or may rely on latching arms carried by the lids which engage retention lips on the container. In either case the separate sealing member, i.e., O-ring or gasket involves not only added manufacturing costs, but is subject to being misplaced or lost during use of the container.
There is a need for a more user friendly food storage container/cover which overcomes the above shortcomings.